Practise Tests
11
The bacteria in a dish doubles every day. If we start with one bacteria on the first day the dish gets completely filled in 30 days.
If we start with two bacteria, in how many days the dish will be half filled?
12
Mr. Sharma uses shed and shoulder shampoo every day. Due to work pressure he lost 1/4th of his hair every year. (Approximately) After how many years will he have 1/4th of hair what he had at the start of usage of shampoo?
13
A man starts going for morning walk every day. The distance walked by him on the first day was 2 km. Every day he walks half of the distance walked on the previous day. What can be the maximum distance walked by him in his lifetime?
14
A basketball is dropped from a height of 100 feet. It bounces back to the each time to a height which is one-half of the last bounce. How far approximately will the ball have travelled before it comes to rest? [E-LITMUS]
Answer : Option 4
Explanation:
15
There are 30 balls of same size and color, one of the ball is heavier than the rest. What is the minimum number of weighing required to find the heaviest ball?
Answer : Option 2
Explanation:
16
There is cask full of milk. E litres are drawn from the cask,it is then filled with water. This process is repeated.now the ratio of milk to water is 16:9.What is the capacity of the cask in litres?
Answer : Option A
Explanation:
Let us assume that initially the cask is having X litres of milk. then
As the cask is full of milk, then we have currently X litres of milk
Now we remove E litres of milk from the cask. So Now
x ltr milk .. 0 ltr water
after first draw and water filling by E ltrs,
x-E ltr milk and E ltr water
after 2nd draw and water filling by E ltrs,
x- [2E-(E^2/x)] and 2E -( E^2)/x ltr water
As per condition
x- [2E-(E^2/x)] /[ 2E -( E^2)/x] = 16/9
solving, we get
x=5E
17
When we perform a digit slide on a number we move its units digit to the front of the number.for eg:the result of a digit slide on 6471 is 1647…let z be the samllest positive integer with 5 as its units digit such that the result of a digit slide on the number equals 4 times the number…how many digits will z have?
Answer : Option B
Explanation:
……5 x 4 = 20
……05 x 4 = 20
……205 x 4 = 820
…..8205 x 4 = 32820
….28205 x 4 = 112820
….128205 x 4 = 512820
so Z will have 6 digits.
18
When a certain number x is multiplied by 27,the product y has all digits as 3s.what is the minimum number of digits x can have?
19
If N = 1! + 2! + 3! + 4!..........+10!, then what is the last digit of ?
Answer : Option C
Explanation:
N= 1!+2!+3!.....+10!
Summing up the factorials gives, N = 1 + 2 + 6 + 24 + 120 + 720 + 5040 + 40320 + 362880 + 3628800 = 4037913.
Now we have to find the last digit of =
So, check the last digit (i.e) 3 ( the cyclicity of 3 is 4)
Divide : = ( Here the remainder is 1)
will be the answer
Therefore = 3
20
A set M contains element all even number between 1 and 23 and all odd numbers 24 and 100. If all the elements of the set are multiplied then how many trailing 0 ( ending with 0), resulting product will have?
Answer : Option D
Explanation:
For trailing zeros, we need to find the number of 5 and 2 available in the given product.
Say Example: 3 x 5 x 2 x 2 x 5 
( we have 2 zeros)
Here in the given question, we have the set M: ( 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22) the even number between 1 and 23, whereas ( 25, 35, 45, 55, 65, 75, 85, 95 ) the odd numbers between 25 and 100
So the total numbers available in the set M = ( 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 25, 35, 45, 55, 65, 75, 85, 95)
In the above set, we have to check 2's and 5's
So the number of trailing zero will be 12 ( as the minimum number of 5 are 12)
